Oral status and homebound status: A 6-year bidirectional exploratory prospective cohort study.

OBJECTIVES: Little is known about the association between oral status and homebound status, and there is a possibility of a bidirectional relationship between them. In this exploratory prospective cohort study, we examined the association between four oral status measurements and being homebound bidirectionally. METHODS: We used 2010-2016 panel data gathered from the Japan Gerontological Evaluation Study. All functionally independent participants aged 65 years or older (n = 26,579) were included in this study. Multiple imputation and Poisson regression were used for analyses. We adjusted for age, sex, education, comorbidity, and depressive symptoms. RESULTS: In the fully adjusted model, the prevalence ratio (PR) of being homebound at follow-up was 1.42 for having <20 remaining teeth, 1.28 for having chewing difficulty, 0.99 for having choking experience, and 0.94 for having dry mouth at baseline. Reversely, being homebound at baseline predicted having chewing difficulty at follow-up (PR = 1.17), while no significant association was demonstrated with having <20 teeth (PR = 1.00), choking experience (PR = 1.06), and dry mouth (PR = 1.02). CONCLUSION: Chewing difficulty and having <20 remaining teeth predicted homebound status after 6 years. Reversely, homebound status at baseline only predicted having chewing difficulty at follow-up. These findings may help to determine the oral frailty assessment measures for older people.

Factors associated with smoking behaviour changes during the COVID-19 pandemic in Japan: a 6-month follow-up study.

BACKGROUND: Smoking behaviour may have changed due to the COVID-19 pandemic, the April 2020 revised smoke-free policy and the high prevalence of heated tobacco product (HTP) use in Japan (10.9% in 2020). This study examined the association between these three events and smoking behaviour changes using 6-month follow-up data from before and during the pandemic. METHOD: Using longitudinal data from an internet survey conducted in February 2020 (baseline) and follow-up in August to September 2020, prevalence ratios (PR) and 95% confidence intervals (95% CIs) for smoking behaviour changes (increase and quit) were calculated using multivariable Poisson regression with adjustments for potential covariates including three event-related five factors: fear of COVID-19, living in a COVID-19 endemic area, workplace smoking rules, self-imposed smoking rules at home and type of tobacco use (cigarette only/HTP only/dual use). A smoker who reported an increase in smoking intensity in the last month was defined as an increase. A smoker who had stopped both cigarettes and HTPs at follow-up was defined as a quit. RESULTS: We analysed 1810 tobacco users (1448 males (80%); mean age 50.8 years±13.2 SD). At baseline, 930 participants used cigarettes only, 293 HTPs only and 587 both. While 214 (11.8%) users increased smoking intensity, 259 (14.3%) quit both tobacco products. Those who feared COVID-19 were less likely to quit (PR=0.77, 95% CI 0.68 to 0.95), while living in a COVID-19 endemic area was not associated with either smoking behaviour change. Workplace smoking rules were not associated with either smoking behaviour change, but those with no home smoking ban were less likely to quit. Compared with cigarette-only users, HTP-only users were more likely to quit (PR=1.57, 95% CI 1.17 to 2.11), while dual users were more likely to increase smoking intensity (PR=1.35, 95% CI 1.01 to 1.79). CONCLUSION: During the pandemic, dual cigarette and HTP use increased smoking intensity, whereas HTP-only use was associated with quitting but fear of COVID-19 and not having a home smoking ban made it harder to quit.

Association among the number of teeth, dental prosthesis use, and subjective happiness: A cross-sectional study from the Japan Gerontological Evaluation study (JAGES).

STATEMENT OF PROBLEM: Little is known about the association between the number of teeth and self-rated happiness or the association between dental prosthesis use and self-rated happiness in an older population. PURPOSE: The purpose of this cross-sectional study was to examine the association between the number remaining of teeth with and without dental prosthesis use and self-rated happiness in an older population. MATERIAL AND METHODS: The survey data from the 2016 Japan Gerontological Evaluation Study (JAGES) on independent participants aged 65 years or older were assessed. The Poisson regression and multiple imputation methods were used for analyses. Covariates were age, sex, marital status, educational attainment, self-rated health, self-rated economic situation, and symptoms of depression. RESULTS: The data from 178 090 participants, 81 489 men (45.8%) and 96 601 women (54.2%), were analyzed, with a mean ±standard deviation age of 73.6 ±6.1 years. Overall, 66.4% of the participants were happy, declining to 45.7% in those who had 0 to 9 teeth and no dental prosthesis (n=3102). It was 61.5% in those who had 0 to 9 teeth and used a dental prosthesis (n=41 424), 56.8% in those who had 10 to 19 teeth and no dental prosthesis (n=6719), 65% in those who had 10 to 19 teeth and used a dental prosthesis (n=31 592), 70.5% in those who had ≥20 teeth and no dental prosthesis (n=52 525), and 70.1% in those who had ≥20 teeth and used a dental prosthesis (n=42 728). The interaction analysis showed that the reduction in the probability of being happy among those with fewer teeth was smaller among those who used a dental prosthesis. CONCLUSIONS: Having a higher number of teeth and using a dental prosthesis were independently associated with being happy. A significant interaction suggested that dental prosthesis use improves happiness among those with moderate to severe tooth loss (<20 remaining teeth).

Challenges and way forward for implementation of sugar taxation in the Middle East and North Africa (MENA).

BACKGROUND: Over consumption of added sugar beyond the World Health Organization (WHO) recommended level of 10% of daily energy intake has well-established negative health consequences including oral diseases. However, the average consumption of added sugar in the Middle East and North Africa region (MENA-World Bank's regional classification) is 70% higher than the WHO recommended level. Imposing taxes on added sugar has been proposed by the WHO to decrease its consumption. Yet, only 21.6% of the total MENA population are covered by taxation policies targeting added sugar. CHALLENGES: Well-recognized challenges for the implementation of sugar taxation in MENA include the tactics used by the food and beverage industry to block these type of policies. However, there are also other unfamiliar hurdles specific to MENA. Historically, there have been incidents of protest and riots partially sparked by increased price of basic commodities, including sugar, in MENA countries. This may affect the readiness of policy makers in the region to impose added sugar taxes. In addition, there are also cultural, lifestyle and consumption behavioural barriers to implementing added sugar taxation. Ultra-processed foods and sugar-sweetened-beverages (SSBs) rich in added sugar are perceived by many in MENA as essential treats regardless of their health risks. Furthermore, some countries even provide subsidies for added sugar. Also, (oral) healthcare providers generally do not engage in policy advocacy mainly due to limited training on health policy. WAYS FORWARD: Here, we discuss these challenges and suggest some ways forward such as (1) support from a health-oriented political leadership, (2) raising public awareness about the health risks of over consumption of sugar, (3) transparency during the policy-cycle development process, (4) providing a free and safe environment for a community dialogue around the proposed policy, (5) training of (oral) healthcare professionals on science communication and policy advocacy in local lay language/dialect, ideally evidence informed from local/regional studies, (6) selecting the appropriate political window of opportunity to introduce a sugar tax policy, and (7) clear and strict conflict of interest regulations to limit the influence of commercial players on health policy.

Exposure to household dysfunction at childhood and later number of teeth among older Japanese adults: A life course study from the Japan Gerontological Evaluation Study.

OBJECTIVES: The aim of this retrospective cohort study was to investigate the life course association between exposure to two household dysfunctions (father violence against mother and parental divorce) at childhood (≤18 years) with later number of remaining teeth (≥65 years) in functionally independent older Japanese population. This was the first study to investigate this research question in the Asian context. METHODS: The Japan Gerontological Evaluation study (JAGES) self-reported retrospective data gathered in 2013 was used (n = 21,604). Each household dysfunction was binary variable (Yes/No), while the five categories of the number of remaining teeth were ≥20, 10-19, 5-9, 1-4, and no teeth. Sex-stratified ordered logistic regression models were used to calculate the odds ratios (OR) of having fewer teeth. The models were adjusted for age, economic adversity in childhood, educational attainment, comorbidities, and smoking status. RESULTS: Overall, 46.4% were men and a total of 1149 participants (5.3%) experienced household dysfunction at childhood [men = 642 (6.4%), women = 507 (4.4%)]. The regression models showed higher OR of having fewer teeth among men who experienced a household dysfunction [OR = 1.16; 95% Confidence interval (CI) = 1.00-1.36] than men who did not. This association was not observed among women [OR = 0.94; 95% CI = 0.79-1.13]. Similar magnitude and direction of the association was observed among men but not among women when the two components of household dysfunction were used separately and aggregately as exposure variables. CONCLUSION: An exposure to a household dysfunction at childhood was associated with having fewer teeth in later life among men but not among women.

Association Between Toothbrushing Habits and COVID-19 Symptoms.

OBJECTIVES: The association between toothbrushing and coronavirus disease 2019 (COVID-19) infections is unknown. The aim of this study was to test the hypothesis that the change in time and frequency of toothbrushing is associated with having COVID-19 symptoms. METHODS: In this 8-month retrospective cohort study, we used the data from the Japan COVID-19 and Society Internet Survey (JACSIS; N = 22,366), which was conducted between August and September 2020. The logistic regression analyses were used to calculate the odds ratios (ORs) of having the 3 main COVID-19 symptoms (high fever, cough, and taste and smell disorder). Confounders were age, sex, educational attainment, equivalised income level, self-rated health, health literacy, and living area. RESULTS: The mean age of the participants was 49 years (SD = ±17.3), and 49.2% were male. Overall 2704 (12.1%) participants changed (increased or decreased) the time and frequency of toothbrushing, whilst 19,662 (87.9%) did not change. Only 60 participants (0.3%) had the 3 main COVID-19 symptoms. All logistic regression models showed that those who had a change in time and frequency of toothbrushing had higher odds of having the 3 main COVID-19 symptoms compared to those who had unchanged time and frequency of toothbrushing. The ORs ranged from 6.00 (95% confidence interval [CI], 3.60-9.99) in the crude model to 4.08 (95% CI, 2.38-6.98) in the fully adjusted model. CONCLUSIONS: The change in time and frequency of toothbrushing from before to after the COVID-19 pandemic was associated with having the 3 main COVID-19 symptoms.

Does remaining teeth and dental prosthesis associate with social isolation? A six-year longitudinal study from the Japan Gerontological Evaluation Study (JAGES).

OBJECTIVES: Social isolation was associated with increased mortality and numerous adverse health outcomes. However, the longitudinal association between oral health and social isolation has not been studied. In this longitudinal prospective cohort study, the association between the number of remaining teeth and dental prosthesis use with social isolation after 6-years follow-up was examined. METHODS: Functionally independent adults aged 65 years or older, who were not socially isolated in 2010, were followed up until 2016 in the Japan Gerontological Evaluation Study. Data from 26 417 participants were analysed after random forest imputation to address missing data. Logistic regression models were used to calculate the odds ratio (OR) for incident social isolation in 2016 after adjusting for age, sex, educational attainment, income, activities of daily living, living area and having depressive symptoms. RESULTS: The mean age of the participants at baseline was 72.3 (SD = 5.0). A total of 1,127 (4.3%) participants were socially isolated at follow-up. Of these, 338 (3.2%) had ≥20 teeth (with or without using dental prosthesis), 171 (3.9%) had 10-19 teeth and used dental prosthesis, 112 (4.2%) had 10-19 teeth and did not use the dental prosthesis, 338 (5.1%) had 0-9 teeth and used dental prosthesis, and 168 (7.6%) had 0-9 teeth and did not use the dental prosthesis. Fully adjusted logistic regression models showed that the OR of incident social isolation was higher for those with fewer teeth; OR = 1.13 (95%CI = 0.96-1.33) for those with 10-19 teeth and OR = 1.36 (95%CI = 1.17-1.58) for those with 0-9 teeth, compared to those with ≥20 teeth. The OR of incident social isolation was lower for those who used a dental prosthesis [OR = 0.90, 95%CI = 0.80-1.02)] compared to those who did not use a dental prosthesis. The interaction between the number of teeth and dental prosthesis use demonstrated that the latter mitigated the incidence of social isolation for participants with tooth loss. Compared to those with ≥20 teeth (with or without prosthesis use), participants with 0-9 teeth that did not use a dental prosthesis were 79% [OR = 1.79, 95%CI = 1.49-2.19] more likely to be socially isolated, whereas participants with 0-9 teeth that used a dental prosthesis were only 23% [OR = 1.23, 95%CI = 1.05-1.45] more likely to be socially isolated. CONCLUSION: Tooth loss was the main predictor for social isolation at follow-up, while no dental prostheses use was an additional risk factor. Dental prosthesis use may reduce the risk of social isolation especially in those with severe tooth loss.

The role of science communication and academic health advocacy in improving population oral health and tackling inequalities.

Oral conditions are a public health problem globally and stark oral health inequalities exist between and within countries. Yet, oral diseases are rarely considered as a health priority and evidence-informed policy generation is challenging. Science communication and health advocacy are critical in that respect. However, due to time limitations, research workload and other factors, academics are usually hindered from participating in such lengthy endeavours. Here, we make the case that 'science communication and health advocacy task forces' should be a priority at academic institutions. The two main duties of these task forces are knowledge transfer about the burden of oral conditions and patterns of inequalities, and their underlying social and commercial determinants, and advocacy and mediation between the stakeholders involved directly or indirectly in policy making. These interdisciplinary task forces, including both academics and non-academics, should collectively have skills that include (1) knowledge about oral health, dental public health and epidemiology, (2) ability to communicate clearly and coherently and make the case in both lay and scientific language terms, (3) familiarity with digital and social media platforms and ability to create visual aids, videos and documentaries, (4) good negotiation skills and (5) maintaining scientific transparency and avoiding getting involved in confrontation with political parties. In the current context, the role of the academic institutions should not only be the production of knowledge, but also the active transferability and application of this knowledge towards public benefit.

Large Contribution of Oral Status for Death Among Modifiable Risk Factors in Older Adults: The Japan Gerontological Evaluation Study (JAGES) Prospective Cohort Study.

BACKGROUND: Oral diseases are preventable and modifiable, but highly prevalent, and cause worse oral status. Particularly, tooth loss has increased in aging societies. However, studies on population-attributable risks of modifiable risk factors for mortality have neglected oral status. This study aimed to investigate the impact of modifiable risk factors on mortality, including oral status. METHODS: This cohort study used the Japan Gerontological Evaluation Study data, including participants aged ≥65 years. The outcome was death between August 2010 and March 2017. We calculated the hazard ratios (HRs) and population attributable fraction (PAF) of modifiable risk factors (oral status, hypertension, depression, heart disease, diabetes, physical activity, smoking status, and alcohol drinking history) for mortality. RESULTS: Analyses included 24 175 men and 27 888 women (mean age: 73.8 [6.0] and 74.2 [6.1], respectively). In men, after adjusting for covariates, having no teeth showed the highest hazard ratio (HR = 1.67, 95% confidence interval [CI] = 1.51-1.86) among the modifiable risk factors, and the PAF for the number of teeth (18.2%) was the second largest following age. In women, having no teeth had the third largest HR (HR = 1.37, 95% CI = 1.19-1.56) following current and former smoking. The PAF for the number of teeth (8.5%) was the sixth largest, which was larger than that of smoking status (4.8%). CONCLUSIONS: In the older population, the HR and PAF of the number of teeth on mortality were sufficiently large compared with other modifiable risk factors, especially in men. Therefore, maintaining good oral status should be included more in global health policies.

Examining the associations between oral health and social isolation: A cross-national comparative study between Japan and England.

In Western countries, the most important part of the face in communication is the mouth, whereas it is the eyes in Asian countries; thus oral health could be more important in social interactions in Western countries. Our aim was to examine differences in the association between oral health status and social isolation among older people by comparing Japan and England. We used cross-sectional information obtained from adults aged 65+ in two ongoing prospective cohort studies: The Japan Gerontological Evaluation Study (JAGES, N = 120,195) and the English Longitudinal Study of Ageing (ELSA, N = 3,958). The dependent variable, social isolation score (SIS) was calculated from five factors (marital status, social support from children, social support from family, social support from friends, and social participation). The independent variables were self-reported number of remaining teeth (0, 1-9, 10-19, ≥20) and denture use (≥20 teeth, 10-19 teeth with denture, 10-19 teeth without denture, 0-9 teeth with denture, 0-9 teeth without denture), while the covariates in the model were: sex, age, educational attainment, self-rated health, number of comorbidities, household annual equivalized income, mental health status, daily living activities, and smoking status. We examined associations between oral health status and SIS by applying an ordered logit model by country. Compared to England, more Japanese participants were socially isolated (1.4% vs. 5.8%), but fewer were edentulous (13.1% vs. 7.7%). In both countries, poorer oral health further increased the odds of being socially isolated. Pooled analysis of the ordered logit model with an interaction term showed that the association of number of remaining teeth with SIS was stronger in edentulous participants and in England (odds ratio = 1.50, 95% Confidence interval:1.26-1.80). In both countries, oral health was associated with social isolation; this association could be stronger in England than in Japan.

Income or education, which has a stronger association with dental implant use in elderly people in Japan?

OBJECTIVES: Although inequalities in dental implant use based on educational level have been reported, no study has used income as a proxy for the socioeconomic status. We examined: (i) income inequalities in implant use; and (ii) whether income or education has a stronger association with implant use in elder Japanese. METHODS: In 2016, a self-reported questionnaire was mailed to participants aged 65 years or older living across Japan as part of the ongoing Japan Gerontological Evaluation Study. We used data from 84,718 respondents having 19 or fewer teeth. After multiple imputation, multi-level logistic regression estimated the association of dental implant use with equivalised income level and years of formal education. Confounders were age, sex, and density of dental clinics in the residential area. RESULTS: 3.1% of respondents had dental implants. Percentages of dental implant use among the lowest (≤ 9 years) and highest (≥ 13 years) educational groups were 1.8 and 5.1, respectively, and among the lowest (0 < 12.2 '1,000 USD/year') and highest (≥ 59.4 '1,000 USD/year') income groups were 1.7 and 10.4, respectively. A fully adjusted model revealed that both income and education were independently associated with dental implant use. Odds ratios for implant use in the highest education and income groups were 2.13 [95% CI = 1.94-2.35] and 4.85 [95% CI = 3.78-6.22] compared with the lowest education and income groups, respectively. From a model with standardised variables, income showed slightly stronger association than education. CONCLUSION: This study reveals a public health problem that even those with the highest education but low income might have limited accessibility to dental implant services.

Performance of the Alex AVX-2 MIMD architecture in learning the NetTalk database.

The process of training neural networks on parallel architectures has been used to assess the performance of so many parallel machines. In this paper, we are investigating the implementation of backpropagation (BP) on the Alex AVX-2 coarse-grained MIMD machine. A host-worker parallel implementation is carried out in order to train different networks to learn the NetTalk dictionary. First, a computational model is constructed using a single processor to complete the learning process. Also, a communication model for the host-worker topology is developed in order to compute the communication overhead in the broadcasting/gathering process. Both models are then used to predict the machine performance when p processors are used and a comparison with the actual measured performance of the parallel architecture implementation is carried out. Simulation results show that both models can be used effectively to predict the machine performance for the NetTalk problem. Finally, a comparison between the AVX-2 NetTalk implementation and the performance of other parallel platforms is presented.

On the improvement of neural cryptography using erroneous transmitted information with error prediction.

Neural cryptography deals with the problem of "key exchange" between two neural networks using the mutual learning concept. The two networks exchange their outputs (in bits) and the key between the two communicating parties is eventually represented in the final learned weights, when the two networks are said to be synchronized. Security of neural synchronization is put at risk if an attacker is capable of synchronizing with any of the two parties during the training process. Therefore, diminishing the probability of such a threat improves the reliability of exchanging the output bits through a public channel. The synchronization with feedback algorithm is one of the existing algorithms that enhances the security of neural cryptography. This paper proposes three new algorithms to enhance the mutual learning process. They mainly depend on disrupting the attacker confidence in the exchanged outputs and input patterns during training. The first algorithm is called "Do not Trust My Partner" (DTMP), which relies on one party sending erroneous output bits, with the other party being capable of predicting and correcting this error. The second algorithm is called "Synchronization with Common Secret Feedback" (SCSFB), where inputs are kept partially secret and the attacker has to train its network on input patterns that are different from the training sets used by the communicating parties. The third algorithm is a hybrid technique combining the features of the DTMP and SCSFB. The proposed approaches are shown to outperform the synchronization with feedback algorithm in the time needed for the parties to synchronize.